It could indicate a problem with the Admin account itself. One of the mostly recommended steps when diagnosing a problem with a Mac (in general) is to create a new account to see if the problem persists. If the problem does not show up in the new account, then it is specific to that account.

My recommendation is to create a new (second) Amin account immediately. If there is a problem with your primary Admin account you don't want to get locked out of your Mac if it goes bork. Then you might try figuring what is wrong with the primary Admin account, or you might just transfer your settings to the new Admin account and delete the one that may have problems.

A piece of advice I heard that I like is to not run your Mac under the Admin account. If there is a piece of malware that gets successfully released, it is very likely going to need an Admin account to be dangerous. On a day to day basis the extra step of very occasionally putting in your password is not onerous. And I like the double check. It makes me stop for a second, pause, and consider whether I am doing something that should have asked for a password... which, of course, I have done. But running on a non-Admin account is an easy way to effectively close one possible vector for a malware infection.

Just saying.

Cheers

__________________My friends, love is better than anger. Hope is better than fear. Optimism is better than despair. So let us be loving, hopeful and optimistic. And we'll change the world. - Jack Layton

A piece of advice I heard that I like is to not run your Mac under the Admin account.

There is no added risk or disadvantage in running an admin vs a standard account on Mac OS X. That mentality is a carry-over from Windows. If you are the sole user of a Mac, there is no need to have more than one account, which, by default, is an admin account.